1. Field of Invention
This invention relates to Radio Frequency Identification (RF-ID). More particularly, the invention relates to indicating RF-ID tags devices, methods and systems for Near Field Communication (NFC).
2. Description of Prior Art
Radio Frequency Identification (RF-ID) is a wireless system that automatically identifies tracks and manages objects via a fast connection between the object and a RF-ID reader. RF-ID principles are described in a publication entitled “Radio Frequency Identification RF-ID: A Basic Primer”, published by the Automatic Identification Manufacturers (AIM), 125 Warrendale-Bayne Road, Warrendale, Pa. 15086, Oct. 23, 2001 and fully incorporated herein by reference. RF-ID tags are also used in Near Field Communication (NFC), which is a combination of RF-ID and interconnection technologies, making it possible to connect any two devices to exchange information or access content and services simply by bringing them close together, e.g. touching each other. Further details on NFC can be obtained from the NFC Forum, 401 Edgewater Place, Suite 601, Waefield, Mass. 01880, USA.
The rising use of RF-ID tags promotes standardization efforts to establish a broadly applicable communication framework between RF-ID tag readers and RF-ID tags. Such a standard is established by European Computer Manufacturers Association (ECMA) International, Geneva, Switzerland in a Near Field Communication (NFC) standard (ECMA-340) dated December 2002. The standard defines communication modes for a near field communication interface and protocol (NFCIP-1) to be used for RF-ID tag readers and RF-ID tags. It also defines both passive and active communication modes to realize a communication network using near field communication enabled devices for networked products and also for consumer equipment. The standard specifies, in particular, modulation schemes, codings, transfer speeds, and frame format of a Radio Frequency/High Frequency (RF/HF) interface, as well as initialization schemes and conditions required for data collision control during initialization. The ECMA Standard also defines a transport protocol including protocol activation and data exchange methods.
In RF-ID systems, an object to be detected, e.g. products, goods, people, etc includes a transponder, as a RF-ID tag, which may be “active” or “passive”, the former including an energy source and the latter relying on received electromagnetic energy to generate a response to a reader interrogation. The tag broadcasts an object identity signal when in the presence of an electromagnetic zone created by the reader. The reader senses and decodes the broadcast signal containing information to identify the object. The object identity is achieved by a connectionless communication that is a connection without a logical connection between the reader and the object. Typically, the reader has a display, where a user can see if the information downloaded from the transponder has been successful or not. In other instances, a user receives immediate response in the form of services, e.g. a door opening.
In those instances where a reader does not contain an output feature, such as a display or provide services, there is a need to know whether an identity signal from a tag has been received by the reader and successful transmission of data from the tag to the reader has occurred. Without such indication, the tag identification process may be unnecessarily repeated, possibly overloading or delaying the reader operation. Thus, a need exists for faster and stronger indication when a RF-ID tag action or a Near Field Communication has been established and completed. Preferably, the tag itself can generate an event and provide feedback to the user that the tag has been successfully interrogated by the reader for the transfer of tag data.
Prior art related to indicating RF-ID tags, includes:
1. U.S. Pat. No. 6,462,647, entitled “Recharegable Active Transponder”, issued Oct. 8, 2002, discloses an active transponder including an antenna for exchanging a radioelectric signal, processing means, an accumulator able to supply a first power supply signal (V1), and storage means able to store the power originating from the received radioelectric signal, and to supply a second power supply signal (V2). This transponder further includes: two means for comparing the two power supply signals to a minimum threshold (Vmin) and, in response, providing two control signals (V3, V4); and charging means controlled by the two control signals, so that the accumulator can be charged, via the charging means, from the stored power. One advantage of such a transponder is that the accumulator can be automatically recharged, as soon as the latter is no longer sufficiently charged to assure the functions of the transponder.
2. USPAP 2002/0106988 entitled “Signaling System And A transponder For Use In The System”, published Aug. 8, 2002, discloses a signaling system includes a plurality of active transponders, an interrogation station and a source of switching signals. Each of the transponders has a microcontroller, a radio transceiver for responding to radio interrogation signals from the interrogation station, the radio transceiver being coupled to the controller by way of switching means which switches the transceiver on or off whilst leaving the microcontroller active, and a passive receiver for receiving switching signals from the source of switching signals, which signals are used by the microcontroller for switching-on or -off the transceiver. Transducers may be coupled to the microcontroller for monitoring environmental features, such as ambient temperature and humidity, and data relating to the features is stored in a RAM in readiness to be relayed to storage means in the interrogation station as and when required. Signals received by the passive receiver enable the radio transceiver to be de-activated in locations, such as in an aircraft, where spurious radiation from the transponder is not permitted and to be re-activated when removed from such a location.
3. USPAP 2003/0030542 entitled “PDA Security System”, published Feb. 13, 2003, discloses a personalized security system for use with a PDA or other portable electronic device. An interrogator signal is transmitted from the portable electronic device, triggering a responsive transmission of a password from an electronic key carried by the wearer. Certain selected functions or all functions of the electronic device are therefore only enabled if the electronic device is within a predetermined operating proximity of the electronic key. Also disclosed is a personal preference monitoring system, for allowing personal preferences to be automatically implemented in response to a user passing within a predetermined distance of an interrogation signal transmitter.
None of the cited art discloses, suggest or teaches an indicating RF-ID tag, preferably self-powered, that provides an event indicating the tag has been successfully or unsuccessfully interrogated by a reader for data transmission, where the event may include voice, light, vibration, odor, change in shape, or different combinations of event indicators.